Electric clock



June 5, 1945. o. H. DICKE ET AL ELECTRIC CLOCK Original Filed Jan. 14, 1939 RNEY INVENTORS OHDic kc and RHDicke BY 6 1. E112 ATT Patented June 5, 1945 ELECTRIC CLOCK Oscar H. Dicke, Rochester, N. Y., and Robert H.

, Dicke, Cambridge, Mass.

Original application January 14, 1939, Serial No. 250,964. Divided and this application January 14, 1944, Serial No. 518,270-

Claims.

This invention relates tomaster clocks wherein the master clocks are, during the presence of alternating current, dominated or otherwise regulated by such alternating current. This application is a divisionof our prior application Ser. No. 398,129, filed June 14, 1941,.which is an im- ,,provement over the prior applications of O. H.

Dlcke, Ser. No. 365,584, filed May 23, 1929, now Patent No. 2,248,164, dated July 8, 1941; Ser. No.

441,109, filed April 2, 1930, now Patent No.

2,331,267, dated October 5, 1943; ser. No. 729,079, filed June 5, 1934, now Patent No. 2,248,165, dated July 8, 1941; Ser. No. 729,080, filed June 5, 1934, now Patent No, 2,185,334, dated January 2, 1940; Ser. No. 239,538, filed November 8, 1938, now Patent. No. 2,359,973, dated October 10, 1944; and Ser. No. 245,700, filed December 14, 1938, now Patent No. 2,313,466, dated March 9, 1943, and the prior application of R. H. Dicke, Ser. No. 39,146, filed September 4, 1935, now Patent No. 2,151,317, dated March 21, 1939, andv constitutes also a division of our co-pending application Ser. No. 250,964, filed January 14, 1939, which became abandoned on June 21, 1941. v

An object of the present invention resides in the provision of master clocks which will operate in sub-synchronism with the frequency of alternating current of regulated frequency so long as current is available and which will keep substantially correct time during a current cessation.

More specifically several of these master clocks each include an oscillatory member which through suitable mechanism drives a time shaft and which includes a local source of energyand means for impulsing such member each time the amplitude of oscillation of such member, falls below a predetermined value in such manner that the successive phase shifts produced by such impulses, whether advancing or retarding phase shifts, cause said member to drive said time shaft to very'accurately reflect the passing of time, and additionally includes alternating current con-" trolled means for dominating said member so as to operate in synchronism with such alternating current and so as to cause this member to be operated at an amplitude above this predetermined value so that this alternating current controlled second form the electro-magnet is controlled by a mercury contact which is closed only if the amplitude of such member is below a predeter-' mined value. In one specific form of these master clocks as illustrated it is proposed to dominate the oscillation of such oscillating member through the medium of a very weak spring driven by a synchronous motor, whereas in a second illustrated form such domination is accomplished through the medium of a frequency dividing impulser which creates one impulse for each predetermined number of cycles of alternating current. As shown this frequency dividing impulser is of compound construction in that two frequency dividing impulsers are proposed to be used and in which an effective impulse is transmitted only when both of these impulsers produce an impulse during the same half cycle of the alter-- nating current. For instance, if one of these impulsers produces a current impulse for each fourth positive wave of current and the other impulser produces an impulse for each fifth positive wave of current and by applying these impulses to a dynamo-meter type structure an effective impulseis produced only for each twentieth impulse of positive polarity.

Other, objects, purposes and characteristic features of the present invention will be in part more particularly pointed outhereinafter and is in part obvious from the accompanying drawing in which- Figs. 1 and 2 illustrate modifications of a master clock embodying the present invention.

Fig. 2A is an enlargement of a portion of the master clock shown in Fig; 2; and

Fig. 23 illustrates a plan view of the mercury tube contactor shown in side elevation in Fig. 2.

means performs a double function of keeping tro-magne't controlled by a mechanical contact I and acting directly on such member and in a.

The master clock shown in Fig. 1 utilizes a two-speed, self-starting, synchronous motor so designed as to operate at one synchronous speed for low voltage excitation and at ahigher synchronous speed for high voltage excitation. The motor is utilized in the following way. During power failure the secondary clocks are not operating, so immediately after a power failure, when this motor is used in a secondary clock, high voltage is fed to the secondary clock for the right length of time to bring it up by the amount which was lost during the power failure. However, as

shown, this motor is not used in a; secondary clock.

Referring now to the master clock of Fig. 1, Pendulum II! with a heavy bob I20 is supported at pivot H8; Bumper I22 is so positioned as to restrict the amplitude of pendulum] i1. Penduwheel lum II 1 is actuated by spring I23 supported or hooked on eccentric pin H5. Eccentric pin H5 is supported on gear wheel I I3 which is driven through gear train H0, III and H2 by selfstarting synchronous motor SM. This gear train drives gear H3 at the same speed as the natural frequency of pendulum H1. The pendulumJIl carries'a side arm. This side arm by a pin supports a flipper I35 which is freely pivoted thereon andhas its center of gravity below the pin. In juxtaposition to the flipper 29 is a contact trigger- I38 provided with a notch I30. When contact I38 is raised due to the engagement of flipper I35 in notch I36 it actuates the contact I33 in engagement'with stationary contact I33.

The remainder of the master clock proper of Fig. 1 consists of a clock gear train and a ratchet mechanism. Pendulum II'I carries a spring actuating lever I24 actuated through spring I23 and pivoted at the top. Limit pins I25 limit the stroke of the actuating lever I24. Lever I24 carries ratchet pawl I26 which actuates ratchet 28 with aid of stationary pawl I21. Ratchet wheel I28 drives clock hands I34 throug gear train I30, I3I and I32.

Fig.1 structure In Fig. l is illustrated a master clock to be used in connection with the system shown in Fi 1.

Referring now to Fig. 1, self-starting synchronous motor SM through gear train IIOII2 drives gear wheel I I3 havingan eccentric pin I I5 upon which is supported a spring IIB under tension. Spring H3 is connected to pendulum H1 and acts thereohq Pendulum H1 is supported from pivot H8 and has a heavy bob I20. Aresilient bumper I22 including a rubber knob I2I is provided to limit the amplitude of the pendu A spring I23 connects lever I24 and pendulum II 1.; Limit pins I25 limit the motion of lever I24. Pawl I28 is pivoted to lever I24 and actuates ratchet wheel I23 with the aid of stationary pawl I23. Pins- I21 guide ratchet I23 and serve to prevent overthrow of the ratchet wheel I 23. Ratchet wheel I28 through gear train I30I32 drives clock hands I34 of which for convenience only one is shown.

Referring again to Fig. 1, the pendulum II1 carries a flipper I35 which is pivoted thereto and which is in juxtaposition to a notched block I30 attached to contact member I33. Contact i38-I33 completes the circuit from battery BA through electro-magnet MG which acts on armature I supported on pendulum II1.

Operation of master clock-Fig. 1

tion. The synchronous motor SM through gear train |I--'I I2 drives gear wheel I I3 supporting eccentric pin I I5. This sinusoidal motion of pin H through spring H6, which is always under I tension, impresses a sinusoidal force on the pendulum III. As is shown in the theory of mechanics, this causes a vibration having the same period as the impressed force to be setup in the pendulum I I1. The strength of the spring III is so adjusted that the amplitude of the resultant vibration is so great for ordinary variation in frequency that the flipper I35 completely clears the block I36 on the swing to the left so that on the return swing to the right the flipper does not catch in the notch of this block I35. Thus under normal operation the contact I30 remains in the normal position and the battery BA is not used. The bumper I2 II 22, although not essential, is preferably used for reasons given below. In practice the strength of the spring H3 is so adjusted as to cause the amplitude of the pendulum II1 to be great enough to strike the bumper I22 having a rubber impact/or I2I. This effectively limits the amplitude of the pendulum H1 and not only protects the clock from damage due totoo great an amplitude but which also enables the clock to operate over a greater variation in frequency of the alternating current.

Coming now tothe second phase of the opera tion of the master clock in case of power failure the synchronous motor SM stops and the spring H5 no longer exerts the above mentioned sinusoidal force. The pendulum now operates as an ordinary damped pendulum slowly decreasing in amplitude. The pendulum bob I20 is made very heavy so as to cause this decrease in amplitude to be very slow. That is, in case or power failure the synchronous motor SM stops and the pendulum II1 operates as a free damped pendulum. The amplitude of pendulum II1 decreases until the flipper I35 fails to completely clear the block I38, and on the return swing the flipper I35 catches in the notch of the block I33 and actuates the contact I30-I39 to circuit closing position. The circuit from the battery BA through contacts I38-I33 to the electro-magnet MG is thereby closed and the'magnet M631 is energized. This causes the magnet M63 to attract the armature HI and so give the pendulum an impulse to increase its amplitude. The amplitude is now great enough so that the flipper I35 clears the block I30 for a number of swings of the pendulum after which, due to reduction in amplitude, the above process is repeated. The flipper I35 and block I35 are so proportioned and positioned that the impulse given to the pendulum I I1 comes near the center of the swing-producing little phase shift in the pendulum. Whatever phase shift is produced is compensated for by adjusting the pendulum fast or slow by the right amount to compensate for this effect and to cause the structure to constitute a very accurate time piece mechanism.

Fig. 2 structure The structure shown in Fig. 2 is a master clock For convenience the clock train, hands, and ratchet actuating mechanism which is identical to that shown in Fig. 1 I23-I34) is omitted from Fig. 2.

Referring now to Fig. 2, the pendulum I42 carries a heavy bob. m, and is supported on knife edge bearings I44I45 (enlarged in Fig. 2A). Pendulum I42 carries a. coil I41 (Fig. 2A) rigidly fixed thereto and having its magnetic axis horizontal. In juxtaposition to the coil I41 is a stationary electro-magnet I43. The coil I41 and electro-magnet I43 are connected on one sid in common to one side of the condensers C and C and on the other side independently through the neon glow lamps G and G, respectively, to the other side of condensers C and C. Condensers C and C.,are charged through the medium of rectiflers r and r' through circuits including re sistances R and R from A. C. power lines delivering alternating current of regulated frequency.

ass-1,01:

Supported on the pendulum I42 is a glass tube I49, shown as a top view in Fig. 23. It contains inert gas and a globule of mercury I", or it may be evacuated. Sealed into the middle arm of this tube I49 are the contact points NH. The contact points II when shunted by mercury globule IIII complete a circuit from the battery BA to? the electro-magnet M(?- acting on armature I53 fixed to pendulum I42. Bumper I54 including a rubber impactor I58 is provided as in Fig. 1.

Fig 2 operation The normal operation of the device shown in Fig. 2 is quite different from that shown in Fig. 1. Instead of a sinusoidal force being applied to the pendulum through a spring, periodic impulses are applied through the medium of the simultaneous discharge of the condensers C and C through glow lamps G and G The operation during power failure is very similar, at least in function, to that of the device shown in Fig. 1. Let us consider first the normal operation.

Referring to Fig. 2, the condensers C 'and C are charged through the rectifiers r and r and resistances R and R until the striking potentials of the glow lamps G and G are reached at which time the condenser is discharged through a glow lamp and the process is repeated. The resistances R and R are so adjusted that the one condenser is discharged, say, every fourth cycle while the other is discharged, say, every fifth cycle. Thus every twenty cycles the condensers are simultaneously discharged. Condenser C is discharged through glow lamp G and coil I",

while condenser (3 is discharged through glow mp G and the winding of magnet H8. The oil I 41 and magnet I48 taken together form a unit which is very similar to the watt-meter or dynam meter and a torque is experienced only when the coil I" and magnet I48 are simultaneously energized. Thus every twentieth cycle the pendulum receives an impulse. These impulses have the same efiect on the pendulum as a spring impressing sinusoidal forces on the pendulum since the fundamental Fourier component is the only one having much efl'ect on the pendulum. 'llgie 1bumper I54 has the same function as in 8'- v The operation during powen'failure is quite similar to that of Fig. 1, the only difference being that the flipper I and contacts l38- I38 of Fig. 1 are replaced by the tube I49. The tube I49, as can be seen in the drawing is warped sothat the sinusoidal motion of the pendulum will cause themercury to move around the circuitous tube. When the amplitude is large the globule will be moving rapidly when it passes the opening oh the short cut branch (see Fig. 23) so that the globule will follow the outside branch. However, when the amplitude has fallen to the correct value the mercury globule will be moving so slowly that it will enter the short cut branch of the tube and in passing through it will momentarily short circuit the contact points III resulting in the energization of the magnet MG and this gives the clock an impulse to increase its amplitude for several pendulum swings during which the mercury I takes the long path after which the above process is repeated.

It is thus seen that in the master clocks illustrated in each of Figs. 1 and 2 the alternatin current not only functions to dominate the pendulum but it also serves as a. cut-out device to cut out the local source of energy, in the form of'a battery, so that no power-o1! relay such as would ordinarily be used is required.

The applicants have thus shown and described several forms of their invention including modifled forms of master clocks, and it should be understood that the master clocks illustrated have been selected to aid in the description of the principles employed and some manners in which these principles may be applied in practicing the invention, and that the invention is not limited to the particular constructions illustrated. It should therefore beunderstood that the present invention is not limited to the specific constructions illustrated except as demanded by the scope of the following claims.

What we claim as new is: n

1. In a sustained power clock, the combination with a source of alternating current having its frequency regulated to correctly manifest the passing of time, an oscillatory, member having a natural frequency of oscillation to substantially correctly manifest the passing of time, a two element electro-magnetso associated with said member that ii intermittently rendered active at approximately the natural frequency of, said member will cause said member to oscillate with said intermittent activities, a condenser and an electronic discharge device connected in series with each of the two elements of said electromagnet, a rectifier and charging resistances connected in series and to said source of alternating current for each of said condensers for intermittently charging said condensers, the condensers and resistances being so constructed and proportioned that one of said electron discharge devices discharges its associated condenser once for each predetermined number of cycles of alternating current and the other electron discharge device discharges its associated condenser once for each but a different predetermined number of cycles of alternating current, whereby said electromagnet is rendered active only once during the product of the two predetermined number of cycles of alternating current to cause said member to be oscillated in sub-synchronism with said alternating current, and means including a local source of energy for maintaining said member oscillating during a current cessation.

2. In a clock; the combination with a source I of alternating current of regulated frequency,

regulated to correctly manifest by cycle summation the passing of time; a pendulum having a natural frequency which is slightly less than a sub-multiple of the average frequencyof said current; a coil which when energized may act on said pendulum; means for applying electric current impulses to said coil including a condenser, an electronic discharge device and said coil in series, and a rectifier for charging said condenser from said source of alternating cur- 1 rent; and means including a local source of,

energy for maintaining sail pendulum oscillating at or above a predetermined amplitude during a current cessation.-

3. In a combined direct and alternating current clock, the combination with a time shaft. means including an oscillatory device which if oscillated advances said shaft directly in accordance with its frequency of oscillation, means ineluding a direct current source for oscillating said oscillatory device at its natural frequency and at an average medium amplitude and which consumes no direct current energy if said oscillatory device is oscillated at a higher amplitude, said oscillatory device having a natural frequency to cause the rotation of said time'shait to'substantially correctly maniiest the passing of time, a source of alternating current having its frequency regulated to correctly manifest the passing of time, and means controlled by said source of alternating current for doing both oscillating said oscillatory device at or above said higher amplitude so that no direct current will be consumed and oscillating said oscillatory device in consonance with the frequency of said alternating current so that said time shaft will correctly manifest the passing of time so long as no alternating current cessation occurs, said last mentioned means including a condenser and a discharge device said condenser being charged from said alternating current source to a predetermined potential in a predetermined number of cycles which is discharged through said discharge device upon reaching said potential.

4.'An all electro-magnetic oscillatory mechanism, operating means for operating such mechanism in subsynchronism with an alternating current when such current is available and for operating it from a local source of current when such alternating current fails comprising, an oscillatory mechanism, a source of alternating current, condenser charging and discharging means producing a flow of current once for each predetermined number of cycles of said alternating current, condenser charging and discharging means producing a how of current for each predetermined but different number of cycles of said alternating current, means producing a magnetic pull upon said oscillatory mechanism only when both of said means produce a flow of cur rent simultaneously, and other wholly electromagnetic means for applying a magnetic actuating force upon said oscillatory mechanism when. its amplitude of operation falls below a predetermined value.

5. An all electro-magnetic oscillatory mechanism, operating means for operating such mechanism in subsynchronism with an alternating current when such current is available and for operating it from a local source of current when such alternating current fails comprising, an oscillatory mechanism, a source of alternating current, condenser charging and discharging means producing a flow of current time for each predemined number of cycles of said alternating current, condenser charglngand discharging means producing a flow of current for each predetermined but different number of cycles of said al ternating current, means producing a magnetic pull upon said oscillatory mechanism only when both of said means produce a flow of current simultaneously, an electro-magnet which when energized acts upon said oscillatory mechanism, a local source oi current, and a mercury contact mechanism which momentarily connects said local source to said elcctro-magnet at a predetermined point in the swing or said oscillatory mechanism only if the amplitude of operation of said oscillatory mechanism falls below a predetermined value.

6. In an all electro-magnetic oscillatory mechanism operating means, the combination with an oscillatory mechanism, a local source of current, anevacuated container having two circuitous paths, a globule of mercury in said container, said container being. so shaped that when mounted to operate with said oscillatory mechanism said will circulate through the other of said paths when the amplitude of oscillation of said mechanism falls below said value, contacts sealed into said container to be shunted by said mercury when said mercury passes through said other path but not when it passes through said one path, an electro-magnet for when energized exerting a force upon said oscillator mechanism, and a circuit including said local source said contacts and said electro-magnet in series.

7. In all electro-magnetic oscillatory mechanism operating means, the combination with an oscillatory mechanism, a local source of current,

an evacuated container having two circuitous paths, 8. globule of mercury in said container, said container being so shaped that when mounted to operate with said oscillatory mechanism said mercury will circulate through one of said paths so long as said oscillatory mechanism oscillates at an amplitude above a predetermined value and will circulate through the other of said paths when the amplitude of oscillation of said mechanism falls below said value, contacts sealed into said container to be shunted by said mercury when said mercury passes through said other path but not when it passes through said one path, an electro-magnet for when energized exerting a force upon said oscillatory mechanism, a circuit including said local source said contacts and said electro-magnet in series, a source of alternating current of regulated frequency, and an all electro-magnetic means governed from said source of alternating current and acting to control said oscillatory means to operate it in subsynchronism with the frequency of said alternating current at a sub-frequency such that one cycle "of the sub-frequency includes the product of the cycles in each cycle of two higher sub-frequencies of said alternating currents which higher sub-frequency each includes a plurality of cycles of said alternating current, whereby said first mentioned sub-frequency has a cycle time which is the product of the cycle times of the two higher sub-Irequencies.

8. An all electro-magnetic oscillatorymechanisrn operating means for operating such mechanism in subsynchronism with an alternating current when such current is available and for operating it from a local source of current when such alternating current fails comprising, an oscillatory mechanism, a source of alternating current, two circuits, means for causing current flow in one of said circuits once only for each predetermined number of, cycles or said alternating current, means for causing current flow in the other of said circuits only once for each prede-l termined but din'erent number pf cycles of said alternating current, electro-magnetic means responsive only when both of said circuits have current flow therein simultaneously forapplying an actuating force on said oscillatory means, and

,\other electro-magnetic means including means mercury will circulate through one of said paths so lon as said oscillatory mechanism oscillates at an amplitude above a predetermined value and Qmtrolled in accordance with the amplitude of oscillation of said oscillatory mechanism for applying an actuating force to "said oscillatory mechanism when its amplitude of operation falls below a predetermined value.

9. An all electro-magnetic oscillatory mechanism operating means for operating such mechanism in subsynchronism with an alterhatingcurrent comprising, an oscillatory mechanism, a source of alternating current, a first and a second circuit, means" for causing the flow of current in said first circuit once only for each pre' determined number of cycles 0'! said alternating current, means for causing the flow of current in said second circuit only once for each predetermined but difierent number of cycles of said alternating current fails comprising, an oscillatory mechanism, a source of alternating current,

i condenser charging and discharging means pronism in synchronism with an alternating current when such current is available andfor operating it from a local source of current when such ducing a flow of current once for each predetermined number of cycles of said alternating current, condenser-charging and discharging means producing a flow oi current for eachpredetermined but different number or cycles of said'alternating eurrent and electro-magnetic means for produc-' ing a magnetic pull upon said oscillatory mechanism only when both 01 said means produce a flow of current simultaneously.

OSCAR H. DICKE.

ROBERT H. DICKE. 

